I get that occasionally when opening projects, adding softsynths, etc.
I refer to it as the "White Screen of Wonder" because you sit there wondering if it's gonna crash but it never has.
I just ignore it.

OK I did some research on my own system and I do occasionally get the white screen. It happens when loading projects that have Session Drummer and Dim Pro. Mainly because I think these synths are loading stuff into RAM while other things happening with the program as well before the project fully opens. It's an annoyance at this point, but no big deal.

Thanks to Bob ...gustabo ...emwhy for helping pinpoint the cause(es) for what may turn out to be a common issue amongst users and in fact a small program overhaul. Once before I reported an issue that turned out to be an underlying cause in Cakewalk's past propensity for crashing under larger project loads in professional environments. Like gustabo & emwhy ... the issue is currently only a minor annoyance. I'm still in a session that won't end til tomorrow and X2a is the production platform. Once Bob and I reach a point of competion in the tech profile he's orchestrated, I will go to Cakewalk with the matter. The Cakewalk tech staff has been extremely helpful in my years' association with the product they represent.